(1) Field of Invention
This invention relates to the field of rotary torso exercise machines.
(2) Description of Prior Art
Rotary torso exercise machines are known in the art. U.S. Pat. No. 4,456,245 discloses an exercise machine designed to provide the user with a means to exercise torso rotation muscles. This machine provides means to vary the resistance to the torso rotation exercise via weights connected to a pulley and cam mechanism. However the machine is quite large and extremely heavy and is therefore primarily suited for use only in a commercial gym or in the largest, most expensive home exercise rooms, its space and budget requirements putting it well beyond the means of the average consumer desiring to purchase a rotary torso exercise machine for home use.
U.S. Pat. No. 5,052,684 discloses another apparatus for training the waist portion of the body. This machine features upper and lower portions, engaged with one another by a drive chain and sprockets, and which turn in opposite directions from one another to accomplish the twisting exercise motion. Brakes are provided as a means for variable resistance to the exercise motion. Though the machine is considerably less bulky than that disclosed in U.S. Pat. No. 4,456,245, and would be suitable for home use, it does not offer collapsibility for ready storage in a small space.
U.S. Pat. No. 6,726,608 B1 discloses a rotary torso exercise machine as well. According to the inventor, its purpose is to assist in stimulating the acupuncture points along the spine simply by allowing the user to twist the body in the rotary manner. Its size makes it suitable for home use however no means of external resistance is provided whatsoever and so resistance (strength) training of the rotary torso muscles cannot be accomplished using the device. Further, it does not offer collapsibility for ready storage in a small space.
U.S. Pat. No. 6,248,047 B1 discloses an exercise device for strengthening the abdominal and lower back muscles. It utilizes an elongated resilient spring member to provide resistance to exercise motions. Although a limited degree of rotary torso exercise could be accomplished using this device, it is not primarily designed to isolate this motion and would certainly be an inefficient way to exercise the torso rotary motion. As the only resistance provided by this machine is in relation to the deviation of the handlebar from the central neutral position, the machine cannot offer resistance to exercise through the full range of rotary torso motion. Further no means for adjusting the quantity of resistance offered is provided.
U.S. Pat. No. Des. 281,712 discloses the ornamental design for a torsion exercising apparatus apparently using two piston in cylinder assemblies for resistance. It appears to be suitable for home use but has no collapsibility features for storage. Similarly, U.S. Pat. No. Des. 344,993 discloses an ornamental design for a torso exercise machine. It also appears to be suitable for home use but likewise has no collapsibility features for storage in small spaces.
The purpose of the present invention is to provide a collapsible rotary torso exercise machine which offers resisted exercise through a full 90 degree range of torso rotation from 45 degrees clockwise orientation to 45 degrees counterclockwise orientation and vice versa. It is also the purpose of this invention to provide such a rotary torso exercise machine which features variable resistance. It is a further purpose of the present invention to provide such a rotary torso exercise machine which can be stored in a small space, is lightweight and readily portable, and which can be manufactured inexpensively enough so as to be within the budget of the average consumer. The present invention is thus ideally suited for home use where both space and monetary concerns are common issues.